Blast furnace cinder notch stopper



Aug. 25, 1942. H. F. 4DE'SCHA 2,294,162

BLAST FURNACE CINDER NOTCH STOPPER Filed Aug. 27, 1940 Patented Aug. 25,Y1942 UNITED STATES PATENT OFFICE BLAST FURNACE CINDER NOTCH STOPPERHerman F. Dobscha, North Braddock, Pa.

Application August 27, 1949, Serial No. 354,439

4 Claims.

This invention relates speclflcally to blast furnace cinder notchStoppers.

ABlast furnaces are provided with a cinder notch through which the slagis removed from the furnace. This opening is water-cooled by anarrangement consisting of an outer frusto-conical shaped cinder cooler,a similarly shaped intermediate Water-cooled element termed the monkeycooler, and a monkey which forms the opening, also water-cooled. Thecinder notch stopper, termed the bott, is provided Ywith internalthreads for mounting upon a cooling water return pipe. Cooling water issupplied tothe bott through a smaller pipe which is concentricallydisposed within the return pipe.

The effect of the cooling water circulated within the bott is to causethe formation of a coatingl of slag about the surface of the bott afterthe latter has been inserted in the monkey. As the monkey and the bottprotrude into the interior of the furnace, these elements are exposed tothe heat of the molten slag. The slag coating which is formed isintended to protect the bott, particularly its nose portion, from thisintense heat.

Heretofore, considerable diflculty has been experienced in removing thebott from the cinder notch to drain off the slag from the underlyingmolten pig iron.

These difficulties have been attributed to the fact that the coolingeffect obtained in the bott is not uniform and is not directed at theareas Where it is most urgently needed, and further, that the protectiveslag coating is not uniformly developed about a given peripheralportionof the bott. These unfavorable conditions are believed tofbe dueto the lack of certain considerations in-the design of prior cindernotch Stoppers or bottaV im.

It isv tri'e"t primary object of my invention to provide ai stopper ofimproved design by the use of R'Elssuf-D m 16m -in prior devices is ofrandom or uncontrolled length, due to the nature of the mounting andfitting arrangements of the variably threaded return pipe to which thebott is secured, cooling water may in some instances be discharged inclose proximity to the interior nose surface of the bott, and in othercases such discharge may take T'fittirgitV Due to the fact that in priordevices 56 place at a considerable distance from the nose surface. Inthe former case, the clearance between the discharge end. of the supplypipe and the nose of the bott is frequently restricted'to such anobjectionable degree that proper circulation of the cooling water isimpeded. Under the latter condition, the maximum cooling effect isobtained, not at the nose interior surface where l it is most urgentlyneeded, but at a zone to the rear thereof. The protective slag coatingon the nose of the bott thus progresses to a lesser depth than isrequired to protect this nose portion of the bott, and in prior devices,early failure frequently occurs. My invention aims to overcome 'theforegoing inherent disadvantages of prior devices.

The invention will be fully apparent from the followingdetaileddisclosure when read in connection with the accompanyingdrawing, and will be defined with particularity in the appended claims.

In the drawing,

Figure 1 is a sectional elevation of a portion of a blast furnaceshowing the cinder notch thereof equipped with a device embodying theinvention.

Figure 2 is an enlarged longitudinal sectional view through a cindernotch stopper of the present invention.

Figure 3 is a sectional view on line III--IlI o1' Figure 2.

In the improved cinder notch stopper of my invention, the external'shape, the wall thickness, and the length of the bott are in generalsomewh'at similar to corresponding elements in known types of cindernotch Stoppers or botts. An outstanding distinction of the presentinvention rea jacketed casting through which cooling water iscirculated. 'I'his cooler carries the usual monkey cooler I4 which isalso a hollow casting vthrough which cooling water is circulated.Projecting forwardly from the monkey cooler I4 is the monkey I8, thelatter projecting inwardly into the blast furnace chamber, as shown. Thecinder notch stopper sometimes referred to as the bott is indicatedgenerally at I8. and as shown, has a generally frusto-conical exteriorsurface adapted to make a snug t with the similar cone-like surface ofthe monkey. I'he cinder notch stopper or bott I8 is formed of cast ironor steel, and is mounted on a pipe 28 having exterior screw threadsformed thereon for engagement with internal threads formed near theouter extremity of the stopper.

Located coaxially within the pipe 28 there is a supply pipe 22 by meansof which cooling medium is introduced into the interior of the cindernotch stopper. In the stopper of the present invention, special meansare provided for maintaining the inlet pipe 22 accurately in position soas to insure that the pipe is properly positioned to uniformlydistribute cooling water. To this end, the cooler of my invention isprovided with an internal spider-like webbed element 1 comprising aninner hollow hub 24 spaced from the outer annular wall 28 of the stopperby a plurality of radial webs 28. The central opening 30 of the hollowhub 24 is of sufficient cross-sectional area to afford free passage ofan adequate flow of cooling water, the water volume and pressure beingapproximately the same as that used in conventional practice. The rearof the hub 24 is provided with an enlarged socket 32 into which extendsthe extremity of the pipe 22, the pipe making a working iit therewith sothat relative movement between the two can take place, due to expansionand contraction, thus providing for accurate centering of the supplypipe 22 within the outlet pipe 20. The distance between the inner end 34of the `hub 24 and the inner surface 38 oi the stopper nose chamber 88is' believed to be somewhat critical, in order to assure maximum coolingeffect upon this nose surface, as well as to obtain a strong scouringand cleansing action from the velocity of the' cooling water impingingupon such inner 'nose surface. It has been demonstrated that forapplication to iron blast furnaces operating at temperaturesapproximately 2700 to 2800 F., using cooling water at the rate ofapproximately ten gallons per minute at a pressure of 20 pounds, adistance of 1% inches between the nose surface 36 and the inner end 34of the hub gives an entirely satisfactory cooling effect and alsoprovides for a strong scouring action sumcient to carry away silt, sandand scale which would otherwise remain or become lodged in the chamber38 adjacent the nose of the'stop- Der. In the stopper or bott of myinvention, it is apparent that the nose portion is at all timessubjected to the maximum cooling effect. Thus the greatest depth ofprotective slag coating will be formed on the exterior thereof. Animportant feature of the described construction is that the plurality ofwebs 28 which -connect the hollow hub 24 with the main body portion ofthe stopper also provides means for increasing the rate of heat transferfrom the outer body portion of the stopper inwardly through such webs tothe cooling water. This rate of heat transfer is further enhanced byforming the stopper of copper, copper alloy, or equivalent metal havinga high degree of heat conductivity. Since the inner hollow hub 24 isintegrally connected with the outer shell-like body of the stopper bythe several webs as shown, a high rate of heat transfer is maintained,and thus increased cooling effect of the water circulating from the pipe22 in the direction of the arrow shown is secured. I'his watercirculation, it will be understood, is froml the inlet pipe 22 throughthe central opening 38 of the hub of the inner webbed element whence itis impinged on the inner nose surface I8, whereupon reverse flow takesplace, the body of water being uniformly distributed and circulatedrearwardly through the multiplicity of separate passages formed by thewebs 28, the water then flowing outwardly, as indicated bythe arrows inFigure 2, through the outlet pipe 20. By utilization of the invention, agreater depth of protective slag coating is formed uniformly over theentire surface of the bott, its life is lengthened, and importantsavings are effected due to such lengthened life and the avoidance ofinterference in normal furnace operations by premature failure such aswas apt to occur with the conventional bott heretofore used.

In the bott or stopper illustrated, the inner element or hollow hub 2.4has been shown and described as integrallyconnected with the outerfrusta-conical shell by the ribs or webs lillustrated. It is to beunderstood, however, that the outer shell may be of one-piececonstruction formed by a casting, and a separate inner portion can beprovided with radial webs arranged to make a snug llt with the innersurface of the outer shell or bodyof the stopper, or radial webs canextend inwardly from the shell and the hollow hub could be formed of aseparate piece.

While I have described quite precisely the specific embodiment of theinvention illustrated, it is to be understod that the above-mentionedand various other modifications may be made without.

departure from the invention as defined in the A appended claims.

. I claim: 1. A blast furnace cinder notch stopper comprising a hollowshell having a `closed nose at one ter from the shell, a cooling mediumsupply pipe opening into the hollow interior of said element and anoutlet pipe communicating with and se- 'cured to the, end of the shellremote from said closed nose whereby a cooling medium introducedinwardly through said hollow element toward the nose is caused to flowrearwardly between the exterior of said, element and the shell inseparate streams defined by said webs to said outlet pipe. 2. In a blastfurnace, a cinder notch and a 4 stopper therefor comprising a hollowfrustoconical shell having at one end a closed nose, an lnner elementhaving on the exterior thereof longitudinalltr disposed radial websextending to the inner surface of the shell thus spacing the elementfrom the shell, said element having a passageway extendinglongitudinally therethrough and opening into the chamber between saidnose and the inner end of said element, acooling medium supply pipecommunicating with said passageway and making a slip-fit therewith atthe end thereof remote from the said nose, and an outlet pipesurrounding the supply pipe and communicating with the end of the shellremote from the closed nose, the device being so constructed andarranged that a cooling medium directed forwardly through said hollowelement toward the nose of the stopper is caused upon contacting thenose to flow rearwardly between the exterior of said element and saidshell in a plurality of separate streams dened by said Webs, thusdistributing the flow of said cooling medium quite uniformly throughoutthe annular space between the shell and said element, said radial websbeing circularly spaced the same distances apart around the exterior ofsaid inner element and being coextensive in length with said element.

3. A blast furnace cinder notch stopper comprising an elongated taperedshell-having a closed nose adapted to extend into the interior of ablast furnace, a hollow element disposed centrally Within the said shelland spaced therefrom by a plurality of radially extending webs spacedequally around the exterior of said element and coextensive in lengththerewith and serving to divide the annular space between the shell andthe interior of the stopper into a plurality of uniform longitudinallyextending passageways of equal cross sectional area, a supply pipemaking a slipt with said element, and an outlet pipe surrounding thesupply pipe and secured to the end of said shell remote from said closednose, the parts of the device thus being so arranged that a coolingmedium directed forwardly through said supply pipe toward the nose ofthe stopper is caused to flow rearwardly through said passageways insubstantially uniform separate streams to said outlet pipe.

4. In a cooling system for blast furnace cinder notch Stoppers, acooling medium supply pipe, an elongated inner element adapted toreceive the delivery end of said supply pipe and having alongitudinalpassageway therethrough, an enclosing shell for said element having aclosed nose spaced from the forward end thereof and providing a returnpassageway between the shell and the element, and a plurality of webscoextensive in length with the element and extended radially therefromto the inner surface of said shell.

HERMAN F. DDBSCHA.

